Two weeks ago, my husband and I took a day trip to the coast. We specifically went to see the Monarch butterfly grove. We've always heard about it but never got there during the right time of the year. They are just now starting to gather at this grove (which they do every year) in San Luis Obispo. The picture was taken through a telescope as you just can't really see it with your naked eye. And apparently they just started and that by the end of the month this grove will be covered with these clusters.
Here's a video of them all clustered. Again, taken through a telescope.